In order to clarify the task of the present invention, one conventional cartridge holder will described with reference to FIGS. 52 to 57 of the accompanying drawings, which is generally designated by numeral 101. The cartridge holder 101 is constructed to hold three identical floppy disc cartridges 201A, 201B and 201C.
As is best shown in FIG. 52, the cartridge holder 101 comprises generally a pair of lid portions 106 and 107, a hinge portion 103 through which the lid portions 106 and 107 are pivotally connected, a catching portion 109 formed on a free end of the lid portion 106 and a caught portion 110 formed on a free end of the other lid portion 107. Each of the lid portions 106 and 107 is formed on an inner surface thereof with a cartridge receiving area 108 or 112 for receiving thereon the cartridge 201A or 201C. The hinge portion 103 is formed on its inner surface with a cartridge gripping part 102 for gripping a side edge of the cartridge 201B. When the lid portions 106 and 107 are pivoted about the hinge portion 103 toward each other and intimately put on each other, that is, when the case 101 assumes a closed condition, the catching and caught portions 109 and 110 become engaged to latch the closed condition of the case 101.
The cartridge gripping part 102 comprises two pairs of laterally extending parallel ridges 102a and 102b which are formed on the inner surface of the hinge portion 103 to define therebetween two aligned grooves (no numerals). The width of each groove is substantially equal to the thickness of the cartridge 201B. While, the cartridge receiving area 108 or 112 comprises first and second engaging lugs 108a and 108b (or, 112a and 112b) formed on lateral ends of the free end portion of the lid portion 106 or 107 and third and fourth engaging stubs 108c and 108d (or, 112c and 112d) formed on lateral ends of the base end portion of the lid portion 106 or 107. As is seen from FIG. 53 which is a longitudinally sectional view of the case 101, each of the first and second engaging lugs 108a and 108b (or, 112a and 112b) has in a below part thereof a gripping gap whose thickness is substantially equal to that of the cartridge 201A. While, the third and fourth engaging stubs 108c and 108d (or 112c and 112d) are spaced from the first and second engaging lugs 108a and 108b (or, 112a and 112b) by a distance corresponding to the lateral length of the cartridge 201A or 201C.
In order to put the three cartridges 201A, 201B and 201C into the cartridge holder 101, the following manual work is usually carried out. That is, in case of the cartridges 201A and 201C, as is seen from FIGS. 52 and 53, each cartridge 201A or 201C is thrust at one side edge into the gripping gaps defined by the first and second engaging lugs 108a and 108b (or, 112a and 112b) and then pressed against the inner surface of the lid portion 106 or 107 having the other side edge resiliently engaged with the third and fourth engaging stubs 108c and 108d (or, 112c and 112d). With this, the cartridges 201A and 201C are brought to their held position in the lid portions 106 and 107. In case of the center cartridge 201B, as is seen from FIG. 53, the same is thrust at one side edge into the aligned grooves defined by the two pairs of parallel ridges 102a and 102b formed on the hinge portion 103. With this, the center cartridge 201B is held by the parallel ridges 102a and 102b while standing on the hinge portion 103 with the other side edge directed upward. Then, the two lid portions 106 and 107 are pivoted about the hinge portion 103 toward each other and closely put on each other. With this, the catching portion 109 becomes engaged with the caught portion 110 to latch the two lid portions 106 and 107, that is, the cartridge holder 101 at the closed condition.
In order to open the cartridge holder 101 and remove the three cartridges 201A, 201B and 201C therefrom, the following manual work is usually needed. First, a certain force is applied to the catching portion 109 with a thumb to release the latched engagement between the catching and caught portions 109 and 110. Then, the two lid portions 106 and 107 are pivoted in their open directions as seen from FIG. 54. Then, the center cartridge 201B is pull out from the two aligned grooves of the parallel ridges 102a and 102b, and then, as is seen from FIG. 53, the inside side edge of the cartridge 201A or 201C is raised from the inner surface of the lid portion 106 or 107 to disengage from the third and fourth engaging stubs 108c and 108d (or, 112c and 112d) and pulled out from the gripping gaps defined by the first and second engaging lugs 108a and 108b (or, 112a and 112b).
However, due to the inherent construction, the abovementioned conventional cartridge holder 101 has the following drawbacks.
First, the manual work for removing the cartridges 201A and 201C from the cartridge receiving areas of the lid portions 106 and 107 is difficult or at least troublesome. That is, although the first and second engaging lugs 108a and 108b (or, 112a and 112b) and the third and fourth engaging stubs 108c and 108d (or, 112c and 112d) can tightly and assuredly hold the cartridge 201A or 201C, they fail to provide an easiness with which the cartridges 201A and 201C can be removed therefrom. That is, as is seen from FIG. 55, when a user wishes to remove the cartridge 201A from the cartridge receiving area of the lid portion 106, he or she has to pull up the inside side edge of the cartridge 201A with his or her finger "F" from the lid portion 201A against a gripping force applied thereto from the third and fourth engaging stubs 108c and 108d. However, in this case, it tends to occur that the finger "F" is injured particularly when the cartridge 201A has been tightly and assuredly held by the lid portion 106, that is, by the first, second, third and fourth engaging lugs and stubs 108a, 108b, 108c and 108d. Furthermore, due to the same reason, it tends to occur that the inside side edge of the cartridge 201A is damaged.
Second, due to the nature of plastic molding, it is difficult to provide the two aligned grooves defined by the two pairs of parallel ridges 102a and 102b with a width suitable for tightly gripping the center cartridge 201B. That is, if the width is not appropriately matched with the thickness of the cartridge 201B, it tends to occur that upon receiving a certain shock under transportation of the cartridge holder 101, the cartridge 201B comes out from the grooves. In this case, the cartridge 201B is forced to play freely in the holder 101 generating uncomfortable noises.
Third, as will be seen from FIG. 56, there is such a possibility that a shutter-mounted side of the cartridge 201B is thrust into the grooves by mistake. This thrusting tends to damage the shutter. Furthermore, as will be seen from FIG. 57, if the opposite side of the cartridge 201B, that is, the side opposite to the shutter-mounted side has been thrust into the grooves, the manual work for pulling out the cartridge 201B from the grooves has to be made by pinching and pulling out the shutter-mounted side of the cartridge 201B with fingers. Of course, this manual work tends to bring about a possibility of damaging the shutter.